Peformance tuning tools

Hi,
I am kind of new to RoR and currently experimenting with a dummy site
of mine. I have MySQL as database.I would like to know if we have any
tools to check database performance. Do we have any plugin for Rad
rails for this purpose?

Thanks in advance,
Sonia Sharma

Your best bet is probably to regularly look at (or tail -f) your
development log file to see how much work, how many queries, your
application is making to your db. It's a surefire way to tune the
amount of SQL you're asking within your application. It's worked for
me!

- J